Mechanism for asphalt mixing plants and the like



oct'. 14, 1958 w. M. MADSEN 2 856,106

, MECHANISM FOR ASPHALT MIXING PLANTS AND THE LIKE Filed Sept. 28, 19552 sheets sheet 1 "VAINVENTOK:

-WaZZer M. Mac sen 1 v 7 BY, 1

Oct. 14, 1958 MECHANISM FOR ASPHALT MIX ING PLANTS AND THE LIKE FiledSept. 28, 19 53 2 Sheets-Sheet 2' Illa/nay haw MECHANISM FUR ASPHALTMIXING PLANTS AND THE LIKE Walter M. Madsen, Arcadia, Califi, assignor,by means assignments, to Ealdwin-Lima-Hamilton orporatrorn Philadelphia,Pa, a corporation of Pennsylvania Application September 28, 1953, SerialNo. 382,533

3 Claims. (Cl. 222485) This invention relates generally to materialmixing apparatus and relates more particularly to improvements inapparatus for mixing paving and road building material, etc.

While the invention has particular utility in connection with abatch-type mixing apparatus and is shown and described as embodied insuch type of mixing apparatus, the use of said invention is not limitedthereto.

Various such batch types of apparatus or plants employ a dryer forheating the rock and sand aggregates, a vibrating screen which screensthe rock and sand into various grades and deposits the screenedaggregates into bins of one or more compartments. This material isdischarged from the various compartments of a bin into the weigh box.Such bins have tapered side walls tapering down to a narrow portionadjacent the bottom plate which contains a single gate aperture.

The aggregate which is screened into the bin segregates, that is, thecoarser particles roll to the sides of the bin and the finer particlesare more or less confined to the center of the compartment. Due to thefact that these aggregates are hot and dry and generally carry with thema substantial percentage of dust, the coarser materials along the sideof the bin are inclined to become locked there due to the coarse rockskeying together with the li er particles of sand and dust falling intothe cavities or interstices between said rocks.

This keying together of said rocks, coupled with the friction developedimmediately adjacent to the bin wall, plus the effect of mechanicalvibration occurring from the vibrating screen of the apparatus andgeneral plant operation tend to cause a locking action at the bin wallcontact with the result that the material in the center of the bin,vertical as it were to the gate opening, flows through the gate opening,leaving the other material against the bin walls dead.

Such coring out or draining of the center column of the bin storagenegatives the above mentioned segregation of the materials. However,periodically, there is a rush of the stabilized aggregate adjacent tothe bin walls which results in the discharge of a batch of primarily thelarger particles which is also undesirable. Further in the operation ofthe plant, the aggregates require heating and any materials lyingagainst the bin wall, particularly on a cool windy day, become cold andwill not mix properly because they chill the viscous bitument with whichthey are mixed.

It is an object of the present invention to provide apparatus which willovercome the above described difficulties.

Another object of the invention is to provide apparatus of thischaracter that is more efi'icient in eiiecting drainage of the bins.

Still another object of the invention is to provide apparatus of thischaracter for elfecting proper draining of the sides and center of thebin with each discharge of aggregate.

Directly beneath the bin is the above referred-to weigh box for Weighingthe several sizes of aggregates contained in the compartments in the binabove said box and it is another object of the invention to provideapparatus of the present character which will fill the Weighing batcheror weigh box, as it is called, so that the upper level of the materialdischarged in said box is more level with a minimum of peaks andvalleys.

Still another object of the invention is to provide apparatus of thischaracter which makes it possible for the bin to yield a greater volumeof material than in previous types of bins.

A further object of the invention is to provide apparatus of thischaracter that is relatively simple in construction and effective inoperation.

Other objects and advantages of the invention will appear in thefollowing part of the specification.

Referring to the drawings, which are for illustrative purposes only,

Fig. l is a plan view of apparatus embodying the present invention;

2 is a side elevation of the same;

Fig. 3 is an end view of such apparatus;

Fig. 4 is a sectional view taken on line 4-4 of Fig. 2;

Fig. 5 is an enlarged sectional view taken on line 55 of Fig. 3; a

6 is an enlarged section taken on line 66 of Fig. 2; and

Fig. 7 is an enlarged section taken on line 77 of Fig. 4-.

Referring more particularly to the drawings, there is shown a bin litfor aggregates which are used in the asphalt mixing plants. The bincomprises end members 11 and 12 and side members 13. The bin tapersdownwardly and is provided with a plurality of transverse partitions 15,16 and 17 which divide said bin into a plurality of compartmentsindicated generally at 20, 21, 22 and 23. Each compartment is of smallercross sectional size at the bottom than at the top and each is providedwith a plurality of discharge openings 25, 26 and 27 located fordischarge into a weight box 3i disposed beneath the bin, said openings25, 26 and 27 being spaced apart laterally and laterally aligned.

The openings 25', 26 and 27 of each compartment are controlled by agate, there being gates 33, 34, 35 and as for the respectivecompartments 2%, 2t, 22 and 23. The gates are similarly constructed sothat but one will be described, for example gate 33.

The gate comprises a channel member having a body portion 38 whichextends transversely of the bin 2% and has lonigtudinally extendingdepending flanges 39 along the respective side edges. Each side of thegate is provided with a plurality of rollers 40 spaced apartlongitudinally of the gate. As shown in Figs. 5, 6 and 7, each side isprovided with two rollers and each roller is to tatably mounted on ashaft 41 secured in the free or upper end of a supporting member 4-2,the lower ends of said members 42 being secured to the flanges 39 by anysuitable means such as, for example, welding or brazing. The rollers 46;are adapted to travel on tracks 4-4 which are arranged horizontally andwhich have upstanding flanges secured to depending sides 46 of angleirons d7 extending transversely of the bin. These angle 1ne.. hersinclude sides 48 which are secured to the bottom 49 of the bin by anysuitable means such as, for example, welding or the like. It is to benoted that the tracks, which have the sides 4-4 and 45, also are anglemembers. The sides of the angle members 57 form sides of chutes for therespective openings 25, 26 and 27, the other sides of said chutes beingdefined by the depending sides of angle pieces 51 which are suitablysecured to the bottom 49 of the bin and which extend transverselybetween the angle members 47 of the respective compartments. The bodyportion 38 of the gate 33 is spaced downwardly, as shown in thedrawings, from the lower or free ends of the chutes of the openings 25,26 and 27. The amount of spacing of the gate from the adjacent ends ofthe chutes for said openings is determined by the size of the materialto be handled by the particular compartment. Where the material isrelatively fine, the gate body is located closer to the lower ends ofthe chutes than where the material is composed of larger pieces in whichcase the spacing is greater, as best shown in connection with gates 34and 35 in Fig. 7. The gate body 38 is provided with a pair of openings55 and 56 which are spaced apart longitudinally with respect to the gateand there are solid portions 58 and 59 at the respective ends of saidgate and an intermediate solid portion 60 between the openings 55 and56. When the gate is in the closed position, the portions 58, 59 and 60are disposed beneath the chutes of the respective openings 27, and 26.When the gate is in the open position, the holes 55 and 56 are inregister with the openings 27, and 26 to permit the flow of materialtherethrough. With the gate in this position, the trailing end 62 (Fig.4) has been moved'past the chute of the opening 25 so that material mayflow therefrom simultaneously with the flow of material from theopenings 26 and 27.

Overflow chutes '70 (Fig. 3) may be provided, said overflow chutes beingof known character.

I claim:

1. In apparatus for mixing paving material and the like: a bin having acompartment defined by side and end walls tapering inwardly toward thebottom of said compartment and a bottom wall extending across the lowerends of said side and end walls, said bottom wall having a firstdischarge opening adjacent the center thereof spaced from the lower endsof said side walls and second discharge openings laterally spaced onopposite sides of said first discharge opening with said dischargeopenings being aligned across the bottom of the compartment, each ofsaid second discharge openings having one side thereof aligned with thejuncture of one side wall and said bottom wall to permit freeunobstructed flow of material along the inclined side walls of saidcompartment through the second discharge openings, a gate forcontrolling discharge of material from said compartment through saidopenings, means mounting said gate parallel to said bottom wall to bemovable from a first position blocking material flow through openings toa second position for discharge of material, said gate havinglongitudinally spaced openings therein with solid portions at each endof said gate and between the openings of the gate, said solid portionsbeing disposed beneath said discharge openings in said first position ofsaid gate and the gate opening being disposed beneath said dischargeopenings in said second position of said gate.

2. In apparatus for mixing paving material and the like: a bin having acompartment defined by side and end walls tapering inwardly toward thebottom of said compartment and a bottom wall extending across the lowerends of said side and end walls, said bottom wall having a firstdischarge opening adjacent the center thereof spaced from the lower endsof said side walls and second discharge openings laterally spaced onopposite sides of said first discharge opening with said dischargeopenings being aligned across the bottom of the compartment, each ofsaid second discharge openings having one side thereof aligned with thejuncture of one side wall and said bottom wall to permit freeunobstructed flow of material along the inclined side walls of saidcompartment through the second discharge openings, a gate forcontrolling discharge of material from said compartment through saidopenings, said gate having a width greater than the width of saiddischarge openings and having longitudinally spaced openings thereinwith solid portions at each end of said gate and between the openings ofthe gate, means mounting said gate parallel to and spaced beneath saidbottom wall to be movable from a first position blocking material flowthrough said openings to a second position for discharge of material,said solid portions being spaced beneath said discharge openings in saidfirst position of said gate whereby material within said compartmentwill flow through said discharge openings onto said solid portions tobridge the space between said gate and said discharge openings to blockfurther material flow, said gate in said second position having the gateopenings disposed beneath said discharge openings.

3. In apparatus for mixing paving material and the like: a bin having acompartment defined by side and end walls tapering inwardly toward thebottom of said compartment and a bottom wall extending across the lowerends of said side and end walls, said bottom wall having a firstdischarge opening adjacent the center thereof spaced from the lower endsof said side walls and second discharge openings laterally spaced onopposite sides of said first discharge opening with said dischargeopenings being aligned across the bottom of the compartment, each ofsaid second discharge openings having one side thereof aligned with thejuncture of one side wall and said bottom wall to permit freeunobstructed flow of material along the inclined side walls of saidcompartment through the second discharge openings, means defining adischarge chute beneath said bottom wall for each of said discharge.

openings, said chutes having open lower ends in a plane substantiallyparallel with said bottom wall, a gate for controlling discharge ofmaterial from said compartment through said chutes, saidgate having awidth greater than the width of said discharge openings and havinglonigtudinally spaced openings therein with solid portions at each endof said gate and between the openings of the gate, means mounting saidgate parallel to and spaced beneath the open lower ends of said chutesto be movable from a first position blocking material flow through saidchutes to a second position for discharge of material, said solidportions being spaced beneath the lower ends of said chutes in saidfirst position of said gate where material within said compartment willflow through said chutes onto said solid portions to bridge the spacebetween said gate and the lower ends of said chutes to block furthermaterial flow, said gate in said second position having the gateopenings disposed beneath the lower ends of said chutes.

References Cited in the file of this patent UNITED STATES PATENTS490,631 Ransome Jan. 24, 1893 622,909 Barney Apr. 11, 1899 687,116Bulkeley Nov. 19, 1901 835,595 Bishop Nov. 13, 1906 1,750,244 Robb Mar.11, 1930 2,079,802 Hauk May 11, 1937 2,642,206 Reed June 16, 19532,737,315 Rose Mar. 6, 1956

